Taxonomy and phylogeny of Auriculariales (Agaricomycetes, Basidiomycota) with descriptions of four new species from south-western China

Abstract

The wood-inhabiting fungi play an integral role in wood degradation and the cycle of matter in the ecological system. They are considered as the “key player” in wood decomposition, because of their ability to produce lignocellulosic enzymes that break down woody lignin, cellulose and hemicellulose. In the present study, four new wood-inhabiting fungal species, Adustochaetealbomarginata, Ad.punctata, Alloexidiopsisgrandinea and Al.xantha collected from southern China, are proposed, based on a combination of morphological features and molecular evidence. Adustochaetealbomarginata is characterised by resupinate basidiomata with cream to buff, a smooth, cracked, hymenial surface, a monomitic hyphal system with clamped generative hyphae and subcylindrical to allantoid basidiospores (12–17.5 × 6.5–9 µm). Adustochaetepunctata is characterised by resupinate basidiomata with cream, a smooth, punctate hymenial surface, a monomitic hyphal system with clamped generative hyphae and subcylindrical to allantoid basidiospores (13.5–18 × 6–8.2 µm). Alloexidiopsisgrandinea is characterised by resupinate basidiomata with buff to slightly yellowish, a grandinioid hymenial surface, a monomitic hyphal system with clamped generative hyphae and allantoid basidiospores (10–12.3 × 5–5.8 µm). Additionally, Alloexidiopsisxantha is characterised by resupinate basidiomata with cream to slightly buff, a smooth hymenial surface, a monomitic hyphal system with clamped generative hyphae and subcylindrical to allantoid basidiospores measuring 20–24 × 5–6.2 µm. Sequences of the internal transcribed spacers (ITS) and the large subunit (nrLSU) of the nuclear ribosomal DNA (rDNA) markers of the studied samples were generated. Phylogenetic analyses were performed with the Maximum Likelihood, Maximum Parsimony and Bayesian Inference methods. The phylogram, based on the ITS+nLSU rDNA gene regions, revealed that four new species were assigned to the genera Adustochaete and Alloexidiopsis within the order Auriculariales, individually. The phylogenetic tree inferred from the ITS sequences highlighted that Ad.albomarginata was retrieved as a sister to Ad.yunnanensis and the species Ad.punctata was sister to Ad.rava. The topology, based on the ITS sequences, showed that Al.grandinea was retrieved as a sister to Al.schistacea and the taxon Al.xantha formed a monophyletic lineage. Furthermore, two identification keys to Adustochaete and Alloexidiopsis worldwide are provided.

Introduction

In forest ecosystems, fungi play an essential ecological role to drive carbon cycling in forest soils, mediate mineral nutrition of plants and alleviate carbon limitations (Tedersoo et al. 2014). The fungal order Auriculariales is a group mainly composed of wood-inhabiting fungi in Agaricomycetes Doweld (Basidiomycota) (Hibbett et al. 2007). The type genus of this order is Auricularia Bull., in which several other gelatinous genera Exidia Fr., Guepinia Fr. and Pseudohydnum P. Karst., comprise important edible and medicinal fungi (Wu et al. 2019; Liu et al. 2022). Therefore, interest in species diversity in gelatinous genera has increased significantly in recent years (Chen et al. 2020; Shen and Fan 2020; Ye et al. 2020; Wang and Thorn 2021; Wu et al. 2021; Tohtirjap et al. 2023).

Contrary to the gelatinous genera, most species in the order Auriculariales are tough, include saprophytic species with resupinate, effused-reflexed, hydnoid, cerebriform, coralloid or pileate basidiomata (Wells and Bandoni 2001; Miettinen et al. 2012; Hibbett et al. 2014; Malysheva and Spirin 2017; Alvarenga et al. 2019; Spirin et al. 2019a, 2019b; Liu et al. 2022; Tohtirjap et al. 2023). Species with the stereoid basidiocarps are widely distributed in many orders of the Agaricomycetes, although they are certainly a minority in the order Auriculariales (Malysheva and Spirin 2017).

The genus Adustochaete Alvarenga & K.H. Larss. was erected by Alvarenga and Larsson and typed by the taxon Ad.rava Alvarenga & K.H. Larss. It is characterised by the resupinate basidiomata, spiny or tuberculate hymenophore, a monomitic hyphal structure with clamp connections on generative hyphae, present cystidia and hyphidia, ellipsoid-ovoid to obconical basidia, cylindrical to broadly cylindrical, straight or curved basidiospores (Alvarenga et al. 2019). The genus Alloexidiopsis L.W. Zhou & S.L. Liu is typified by Al.schistacea L.W. Zhou & S.L. Liu, which is c characterised by annual, resupinate basidiomata, smooth or with sterile spines hymenophore, a monomitic hyphal structure with clamp connections on generative hyphae, present cystidia and hyphidia, ellipsoid to ovoid, septate basidia, and cylindrical to broadly cylindrical, slightly curved (allantoid) basidiospores (Liu et al. 2022). Based on the MycoBank database (http://www.mycobank.org, accessed on 25 July 2024) and the Index Fungorum (http://www.indexfungorum.org, accessed on 25 July 2024), the genera Adustochaete and Alloexidiopsis have registered four and six species, respectively (Alvarenga et al. 2019; Guan et al. 2020; Hyde et al. 2020; Li et al. 2022a, 2022b; Li and Zhao 2022; Liu et al. 2022; Dong et al. 2024).

Classification of the kingdom of fungi has been updated continuously, based on the frequent inclusion of data from DNA sequences in many phylogenetic studies (Wijayawardene et al. 2020, 2022). Based on the early embrace of molecular systematics by mycologists, both the discovery and classification of fungi, amongst the more basal branches of the tree, are now coming to light from genomic analyses and environmental DNA surveys that have been conducted (James et al. 2020). Based on both the morphological and phylogenetic evidence, the generic concepts of Eichleriella Bres., Hirneolina (Pat.) Bres. and Tremellochaete Raitv. were revised, in which Malysheva and Spirin (2017) proposed that the genus Heteroradulum Lloyd ex Spirin and Malysheva was validated. The genus Eichleriella was accepted to be a monophyletic genus, while both genera Exidiopsis (Bref.) Möller and Heterochaete Pat. seemed to be synonymous, with priority given to the latter genus (Malysheva and Spirin 2017; Alvarenga et al. 2019; Alvarenga and Gibertoni 2021). However, certain species of Exidiopsis, even sequenced ones such as E.calcea (Pers.) K. Wells and E.grisea (Bres.) Bourdot & Maire, still have no appropriate placement at the generic level (Malysheva and Spirin 2017; Li et al. 2022a; Liu et al. 2022).

In recent years, the species diversity of the resupinate Auriculariales have been described or better defined using morphological and molecular analyses and the results showed the hidden diversity of this group and several corticioid genera, for example, Adustochaete, Alloexidiopsis, Amphistereum Spirin & Malysheva, Crystallodon Alvarenga, Heteroradulum, Metulochaete Alvarenga, Proterochaete Spirin & Malysheva and Sclerotrema Spirin & Malysheva, which have been established and described, based on the morphological and phylogenetic studies (Malysheva and Spirin 2017; Alvarenga et al. 2019; Spirin et al. 2019a, 2019b; Alvarenga and Gibertoni 2021; Liu et al. 2022).

During investigations on wood-inhabiting fungi in the Yunnan-Guizhou Plateau, China, many specimens were collected. To clarify the placement and relationships of these specimens, we carried out a phylogenetic and taxonomic study, based on the ITS+nLSU and ITS sequences. These specimens were assigned to the genera Adustochaete and Alloexidiopsis within the order Auriculariales. Therefore, four new species Ad.albomarginata, Ad.punctata, Al.grandinea and Al.xantha are proposed with description and illustrations, based on the morphological characteristics and phylogenetic analyses.

Materials and methods

Sample collection and herbarium specimen preparation

The fresh fruiting bodies were collected on the fallen angiosperm branches from Dali, Dehong, Diqing, Lincang and Zhaotong of Yunnan Province, China. The samples were photographed in situ and fresh macroscopic details were recorded. Photographs were recorded by a Nikon D7100 camera. All the photos were focus-stacked using Helicon Focus software. Macroscopic details were recorded and transported to a field station where the fruit body was dried on an electronic food dryer at 45 °C. Once dried, the specimens were sealed in an envelope and zip-lock plastic bags and labelled (Zhang et al. 2024). The dried specimens were deposited in the Herbarium of the Southwest Forestry University (SWFC), Kunming, Yunnan Province, China.

Morphology

The macromorphological descriptions were based on field notes and photos captured in the field and lab. The colour terminology follows Petersen (1996). The micromorphological data were obtained from the dried specimens after observation under a light microscope with a magnification of 10 × 100 oil (Zhao et al. 2023). Sections mounted in 5% potassium hydroxide (KOH) and 2% phloxine B dye (C₂₀H₂Br₄C_l4Na₂O₅) and we also used other reagents, including Cotton Blue and Melzer’s reagent to observe micromorphology following Wu et al. (2022b). To show the variation in spore sizes, 5% of measurements were excluded from each end of the range and shown in parentheses. At least thirty basidiospores from each specimen were measured. Stalks were excluded from basidia measurements and the hilar appendage was excluded from basidiospores measurements. The following abbreviations are used: KOH = 5% potassium hydroxide water solution, CB– = acyanophilous, IKI– = both inamyloid and non-dextrinoid, L = mean spore length (arithmetic average for all spores), W = mean spore width (arithmetic average for all spores), Q = variation in the L/W ratios between the specimens studied, Q_m represented the average Q of basidiospores measured ± standard deviation and n = a/b (number of spores (a) measured from given number (b) of specimens).

Molecular phylogeny

The CTAB rapid plant genome extraction kit-DN14 (Aidlab Biotechnologies Co., Ltd., Beijing, China) was used to obtain genomic DNA from the dried specimens according to the manufacturer’s instructions. The ITS region was amplified with ITS5 and ITS4 primers (White et al. 1990). The nLSU region was amplified with the LR0R and LR7 (Vilgalys and Hester 1990; Rehner and Samuels 1994). The PCR procedure for ITS was as follows: initial denaturation at 95 °C for 3 min, followed by 35 cycles at 94 °C for 40 s, 58 °C for 45 s and 72 °C for 1 min and a final extension of 72 °C for 10 min. The PCR procedure for nLSU was as follows: initial denaturation at 94 °C for 1 min, followed by 35 cycles at 94 °C for 30 s, 48 °C for 1 min and 72 °C for 1.5 min and a final extension of 72 °C for 10 min. The PCR products were purified and sequenced at Kunming Tsingke Biological Technology Limited Company (Yunnan Province, P.R. China). The newly-generated sequences were deposited in NCBI GenBank (Table 1).

Table 1.

List of species, specimens, and GenBank accession number of sequences used in this study.

Species Name	Sample No.	GenBank Accession No.		Country	References
		ITS	nLSU
Adustochaetealbomarginata	CLZhao 22774 *	PP852049	PP849033	China	Present study
Adustochaeteinterrupta	LR 23435	MK391518	MK391527	Brazil	Alvarenga et al. (2019)
Adustochaetenivea	RLMA 531	MN165954	MN165989	USA	Liu et al. (2022)
Adustochaetepunctata	CLZhao 29669	PP852050	—	China	Present study
Adustochaetepunctata	CLZhao 29671	PP852051	PP849034	China	Present study
Adustochaetepunctata	CLZhao 29675 *	PP852052	PP849035	China	Present study
Adustochaetepunctata	CLZhao 29685	PP852053	PP849036	China	Present study
Adustochaetepunctata	CLZhao 29686	PP852054	PP849037	China	Present study
Adustochaetepunctata	CLZhao 29706	PP852055	—	China	Present study
Adustochaetepunctata	CLZhao 29710	PP852056	PP849038	China	Present study
Adustochaetepunctata	CLZhao 29711	PP852057	PP849039	China	Present study
Adustochaeterava	RC 841	MK391516	—	Brazil	Alvarenga et al. (2019)
Adustochaeterava	KHL 15526	MK391517	MK391526	Brazil	Alvarenga et al. (2019)
Adustochaeteyunnanensis	CLZhao 8212	MZ911964	MZ950629	China	Li and Zhao (2022)
Adustochaeteyunnanensis	CLZhao 4671	MZ911965	—	China	Li and Zhao (2022)
Adustochaeteyunnanensis	CLZhao 4401	MZ911966	MZ950630	China	Li and Zhao (2022)
Alloexidiopsisaustraliensis	LWZ 20180514-18	OM801934	OM801919	China	Liu et al. (2022)
Alloexidiopsisaustraliensis	LWZ 20180513-22	OM801933	OM801918	China	Liu et al. (2022)
Alloexidiopsiscalcea	LWZ 20180904-14	OM801935	OM801920	China	Liu et al. (2022)
Alloexidiopsiscalcea	MW 331	AF291280	AF291326	Germany	Weiß and Oberwinkler (2001)
Alloexidiopsisgrandinea	CLZhao 33798 *	PP852058	—	China	Present study
Alloexidiopsisgrandinea	CLZhao 34279	PP852059	—	China	Present study
Alloexidiopsisnivea	CLZhao 11204	MZ352947	MZ352938	China	Li et al. (2022a)
Alloexidiopsisnivea	CLZhao 11210	MZ352948	MZ352939	China	Li et al. (2022a)
Alloexidiopsisschistacea	LWZ 20200819-21a	OM801939	OM801932	China	Liu et al. (2022)
Alloexidiopsisxantha	CLZhao 25093 *	PP852060	PP849040	China	Present study
Alloexidiopsisyunnanensis	CLZhao 8106	MT215569	MT215565	China	Guan et al. (2020)
Alloexidiopsisyunnanensis	CLZhao 4023	MT215568	MT215564	China	Guan et al. (2020)
Amphistereumleveilleanum	FP-106715	KX262119	KX262168	USA	Malysheva and Spirin (2017)
Amphistereumschrenkii	HHB 8476	KX262130	KX262178	USA	Malysheva and Spirin (2017)
Aporpiumcaryae	Miettinen 14774	JX044145	—	Finland	Miettinen et al. (2012)
Aporpiumcaryae	WD 2207	AB871751	AB871730	Japan	Sotome et al. (2014)
Auriculariaauricula-judae	JT 04	KT152099	KT152115	UK	Tohtirjap et al. (2023)
Auriculariacornea	Dai 13621	MZ618936	MZ669905	China	Tohtirjap et al. (2023)
Auriculariapolytricha	TUFC 12920	AB871752	AB871733	Japan	Sotome et al. (2014)
Auriculariatibetica	Dai 13336	MZ618943	MZ669915	China	Tohtirjap et al. (2023)
Bourdotiagalzinii	Otto MiettinenX3067	MG757511	MG757511	Spain	Malysheva et al. (2018)
Crystallodonsubgelatinosum	RC 1609-URM93444	MN475884	MN475888	Brazil	Alvarenga and Gibertoni (2021)
Crystallodonsubgelatinosum	TBG BF-18001-URM93445	MN475885	MN475889	Brazil	Alvarenga and Gibertoni (2021)
Ductiferasucina	KW3886	AY509551	AY509551	Canada	Liu et al. (2022)
Eichleriellabactriana	TAAM 55071	KX262121	KX262170	Russia	Malysheva and Spirin (2017)
Eichleriellacrocata	TAAM 101077	KX262100	KX262147	Russia	Malysheva and Spirin (2017)
Eichleriellaleucophaea	Barsukova LE 303261	KX262111	KX262161	Russia	Malysheva and Spirin (2017)
Eichleriellatenuicula	ValCB 1	MK391515	MK391525	Brazil	Alvarenga et al. (2019)
Elmerinacladophora	Miettinen 14314	MG757509	MG757509	Indonesia	Malysheva et al. (2018)
Elmerinasclerodontia	Miettinen 16431	MG757512	MG757512	Malaysia	Malysheva et al. (2018)
Exidiaglandulosa	YC Dai 21232	MT663362	MT664781	China	Wu et al. (2020)
Exidiaglandulosa	YC Dai 21233	MT663363	MT664782	China	Wu et al. (2020)
Exidiapithya	MW 313	AF291275	AF291321	Germany	Weiß and Oberwinkler (2001)
Grammatuslabyrinthinus	Yuan 1600	KM379139	KM379140	China	Alvarenga et al. (2019)
Grammatussemis	OM10618	KX262146	KX262194	China	Malysheva and Spirin (2017)
Heteroradulumadnatum	LR 23453	KX262116	KX262165	Mexico	Tohtirjap et al. (2023)
Heteroradulumkmetii	VS 6466	KX262104	KX262152	Russia	Malysheva and Spirin (2017)
Hyalodonpiceicola	Spirin 2689	MG735414	MG735422	Russia	Spirin et al. (2019a)
Hyalodonpiceicola	Spirin 11063	MG735415	MG735423	Russia	Spirin et al. (2019a)
Mycostillavermiformis	Spirin 11330	MG735417	MG735425	Russia	Spirin et al. (2019a)
Mycostillavermiformis	OF 188059	MG735418	—	Russia	Spirin et al. (2019a)
Myxariumcinnamomescens	OF160494	KY801882	KY801909	Russia	Spirin et al. (2018)
Myxariumgrilletii	VS9016	MK098896	MK098944	Russia	Spirin et al. (2019b)
Myxariumhyalinum	TL2012 443455	KY801880	KY801907	Russia	Spirin et al. (2018)
Myxariumlegonii	VS 8986	MK098899	MK098947	Russia	Spirin et al. (2019b)
Protodaedaleafoliacea	Miettinen 13 054	MG757507	MG757507	Finland	Malysheva et al. (2018)
Protodaedaleahispida	Spirin 5139	MG757510	MG757510	Finland	Malysheva et al. (2018)
Protodontiaafricana	AS 171126 1104	MK098978	MK098973	Russia	Spirin et al. (2019b)
Protohydnumcartilagineum	SP 467240	MG735419	MG735426	Russia	Malysheva et al. (2018)
Protomeruliusdubius	VS 3019	MK484041	MK480553	Russia	Spirin et al. (2019a)
Protomeruliusminor	KHL 15937	MK484060	MK480569	Russia	Spirin et al. (2019a)
Protomeruliussubstuppeus	O 19171	JX134482	JQ764649	China	Spirin et al. (2019a)
Pseudohydnumgelatinosum	F14063	AF384861	AF384861	Canada	Weiß and Oberwinkler (2001)
Pseudohydnumgelatinosum	AFTOL ID1875	DQ520094	DQ520094	Germany	Lutzoni et al. (2004)
Stypellopsisfarlowii	Larsson 12337	MG857095	MG857099	Russia	Spirin et al. (2018)
Stypellopsishyperborea	J Norden 9751	MG857097	MG857101	Russia	Spirin et al. (2018)
Tremellochaeteatlantica	URM90199	MG594381	MG594383	Brazil	Alvarenga et al. (2019)
Tremellochaetejaponica	TAA 42689	AF291274	AF291320	Russia	Weiß and Oberwinkler (2001)
Tremiscushelvelloides	AFTOL ID1680	DQ520100	DQ520100	Germany	Lutzoni et al. (2004)
Sistotremabrinkmannii	isolate 236	JX535169	JX535170	Netherlands	Alvarenga and Gibertoni (2021)

New species is shown in bold; * is shown type material, holotype.

The sequences were aligned in MAFFT v. 7 (Katoh et al. 2019) using the G-INS-i strategy. The alignment was adjusted manually using AliView v. 1.27 (Larsson 2014). The dataset was aligned first and then the sequences of ITS+nLSU were combined with Mesquite v. 3.51. The combined ITS+nLSU sequences and ITS datasets were used to infer the position of the new species and related species. The sequence of Sistotremabrinkmannii (Bres.) J. Erikss. obtained from GenBank was used as an outgroup to root trees in the ITS+nLSU analysis (Fig. 1) in the order Auriculariales (Tohtirjap et al. 2023). The sequence of Amphistereumleveilleanum (Berk. & M.A. Curtis) Spirin & Malysheva obtained from GenBank was used as an outgroup to root trees in the ITS analysis in the genus Adustochaete (Fig. 2). The sequence of Heteroradulumkmetii (Bres.) Spirin & Malysheva obtained from GenBank was used as an outgroup to root trees in the ITS analysis in the genus Alloexidiopsis (Fig. 3).

Figure 1.

Maximum parsimony strict consensus tree illustrating the phylogeny of Adustochaete and Alloexidiopsis and related genera in the order Auriculariales, based on ITS+nLSU sequences. Branches are labelled with Maximum Likelihood bootstrap value ≥ 70%, parsimony bootstrap value ≥ 50% and Bayesian posterior probabilities ≥ 0.95.

Figure 2.

Maximum parsimony strict consensus tree illustrating the phylogeny of the two new species and related genera in the genus Adustochaete, based on ITS sequences. Branches are labelled with Maximum Likelihood bootstrap value ≥ 70%, parsimony bootstrap value ≥ 50% and Bayesian posterior probabilities ≥ 0.95.

Figure 3.

Maximum parsimony strict consensus tree illustrating the phylogeny of the two new species and related genera in the genus Alloexidiopsis, based on ITS sequences. Branches are labelled with Maximum Likelihood bootstrap value ≥ 70%, parsimony bootstrap value ≥ 50% and Bayesian posterior probabilities ≥ 0.95.

Maximum Parsimony (MP), Maximum Likelihood (ML) and Bayesian Inference (BI) analyses were applied to the combined three datasets following a previous study (Zhao and Wu 2017) and the tree construction procedure was performed in PAUP* v. 4.0b10 (Swofford 2002). All of the characters were equally weighted and gaps were treated as missing data. Using the heuristic search option with TBR branch swapping and 1000 random sequence additions, trees were inferred. Maxtrees were set to 5000, branches of zero length were collapsed and all parsimonious trees were saved. Clade robustness was assessed using bootstrap (BT) analysis with 1000 replicates (Felsenstein 1985). Descriptive tree statistics, tree length (TL), the consistency index (CI), the retention index (RI), the rescaled consistency index (RC) and the homoplasy index (HI) were calculated for each maximum parsimonious tree generated. The multiple sequence alignment was also analysed using Maximum Likelihood (ML) in RAxML-HPC2 on XSEDE v. 8.2.8 with default parameters (Miller et al. 2012). Branch support (BS) for ML analysis was determined by 1000 bootstrap replicates.

jModelTest v. 2 (Darriba et al. 2012) was used to determine the best-fit evolution model for each dataset for the purposes of Bayesian Inference (BI), which was performed using MrBayes 3.2.7a with a GTR+I+G model of DNA substitution and a gamma distribution rate variation across sites (Ronquist et al. 2012). The first one-quarter of all the generations were discarded as burn-in. The majority-rule consensus tree of all the remaining trees was calculated. Branches were considered significantly supported if they received a Maximum Likelihood bootstrap value (BS) of > 70%, a Maximum Parsimony bootstrap value (BT) of > 70% or Bayesian Posterior Probabilities (BPP) of > 0.95.

Results

Sequence similarity search

The results of BLAST queries in NCBI, based on ITS and nLSU separately, showed the sequences producing significant alignment descriptions:

Adustochaetealbomarginata: in ITS BLAST results, Ad.rava, Exidiasaccharina Fr., Ea.qinghaiensis S.R. Wang & Thorn, Ad.nivea Alvarenga and Exidiopsismucedinea (Pat.) K. Wells were found as the top ten taxa (maximum record descriptions: Max score 830; Total score 830; Query cover 96%; E value 0.0; Ident 92.93%). In nLSU BLAST results, Alloexidiopsisyunnanensis (C.L. Zhao) L.W. Zhou & S.L. Liu, Auriculariaasiatica Bandara & K.D. Hyde, Au.brasiliana Y.C. Dai & F. Wu and Steccherinumnandinae (F. Wu, P. Du & X.M. Tian) Z.B. Liu, Y.C. Dai & Jing Si were found as the top ten taxa (maximum record descriptions: Max score 2398; Total score 2398; Query cover 98%; E value 0.0; Ident 98.60%).

Adustochaetepunctata: in ITS BLAST results, Ad.rava, Ad.nivea, Exidiopsismucedinea and Exidiacandida Lloyd were found as the top ten taxa (maximum record descriptions: Max score 959; Total score 959; Query cover 96%; E value 0.0; Ident 96.74%). In nLSU BLAST results, Ad.rava, Ad.yunnanensis Y.F. Li & C.L. Zhao., Auriculariathailandica Bandara & K.D. Hyde, Au.scissa Looney, Birkebak & Matheny, Au.nigricans (Sw.) Birkebak, Looney & Sánchez-García and Alloexidiopsisyunnanensis were found as the top ten taxa (maximum record descriptions: Max score 2464; Total score 2464; Query cover 98%; E value 0.0; Ident 99.34%).

Alloexidiopsisgrandinea: in ITS BLAST results, Ad.nivea and Al.schistacea were found as the top ten taxa (maximum record descriptions: Max score 861; Total score 861; Query cover 91%; E value 0.0; Ident 94.94%).

Alloexidiopsisxantha: in ITS BLAST results, Al.sinensis J.H. Dong & C.L. Zhao was found as the top ten taxa (maximum record descriptions: Max score 832; Total score 832; Query cover 98%; E value 0.0; Ident 92.42%). In nLSU BLAST results, Al.sinensis and Al.yunnanensis were found as the top ten taxa (maximum record descriptions: Max score 2457; Total score 2457; Query cover 99%; E value 0.0; Ident 99.05%).

The aligned dataset comprised 70 specimens representing 53 species. Four Markov chains were run for two runs from random starting trees, each for two million generations for the combine ITS+nLSU (Fig. 1) dataset with trees and parameters sampled every 1000 generations. The dataset had an aligned length of 2333 characters, of which 1301 characters are constant, 368 are variable and parsimony uninformative and 664 are parsimony informative. Maximum parsimony analysis yielded 120 equally parsimonious trees (TL = 4342, CI = 0.4000, HI = 0.6000, RI = 0.5288 and RC = 0.2115). The best model for the ITS+nLSU dataset, estimated and applied in the Bayesian analysis, was SYM+I+G. Both Bayesian analysis and ML analysis resulted in a similar topology to MP analysis with an average standard deviation of split frequencies = 0.008542 (BI) and the effective sample size (ESS) for Bayesian analysis across the two runs is double of the average ESS (avg. ESS) = 395.5.

The aligned dataset comprised 17 specimens representing seven species. Four Markov chains were run for two runs from random starting trees, each for 0.5 million generations for the ITS (Fig. 2) dataset with trees and parameters sampled every 1000 generations. The dataset had an aligned length of 522 characters, of which 413 characters are constant, 47 are variable and parsimony uninformative and 62 are parsimony informative. Maximum parsimony analysis yielded four equally parsimonious trees (TL = 161, CI = 0.8075, HI = 0.1925, RI = 0.8306 and RC = 0.6707). The best model for the ITS dataset, estimated and applied in the Bayesian analysis, was SYM+G. Both Bayesian analysis and ML analysis resulted in a similar topology to MP analysis with an average standard deviation of split frequencies = 0.006786 (BI) and the effective sample size (ESS) for Bayesian analysis across the two runs is double the average ESS (avg. ESS) = 617.

The aligned dataset comprised 13 specimens representing eight species. Four Markov chains were run for two runs from random starting trees, each for 0.3 million generations for the ITS (Fig. 3) dataset with trees and parameters sampled every 1000 generations. The dataset had an aligned length of 562 characters, of which 417 characters are constant, 64 are variable and parsimony uninformative and 81 are parsimony informative. Maximum parsimony analysis yielded two equally parsimonious trees (TL = 218, CI = 0.784, HI = 0.2156, RI = 0.7814 and RC = 0.6129). The best model for the ITS dataset, estimated and applied in the Bayesian analysis, was SYM+G. Both Bayesian analysis and ML analysis resulted in a similar topology to MP analysis with an average standard deviation of split frequencies = 0.007707 (BI) and the effective sample size (ESS) for Bayesian analysis across the two runs is double of the average ESS (avg. ESS) = 639.5.

The phylogram, based on the combined ITS+nLSU sequences (Fig. 1) analysis, showed that four new species Ad.albomarginata, Ad.punctata, Al.grandinea and Al.xantha were assigned to the genera Adustochaete and Alloexidiopsis within the order Auriculariales, individually. The phylogenetic tree, based on ITS sequences (Fig. 2), revealed that Ad.albomarginata was retrieved as a sister to Ad.yunnanensis. The taxon Ad.punctata was sister to Ad.rava. The topology, based on the ITS sequences (Fig. 3), revealed that Al.grandinea was retrieved as a sister to Al.schistacea and the species Al.xantha formed a monophyletic lineage.

Taxonomy

. Adustochaete albomarginata

J.H Dong & C.L. Zhao sp. nov.

FE1AB077-33E7-57BC-81AB-45982E09F628

854168

Figs 4 , 5 , 6

Figure 4.

Basidiomata of Adustochaetealbomarginata in general and detailed views (CLZhao 22774, holotype). Scale bars: 1 cm (A); 1 mm (B).

Figure 5.

Sections of hymenium of Adustochaetealbomarginata (holotype, CLZhao 22774) A basidiospores B basidia C cystidia D hyphidia. Scale bars: 20 µm (A–D); 10 × 100 Oil.

Figure 6.

Microscopic structures of Adustochaetealbomarginata (holotype, CLZhao 22774) A basidiospores B basidia C basidioles D cystidia E hyphidia F part of the vertical section of hymenium. Scale bars: 10 µm (A–F).

Diagnosis.

Differs from other Adustochaete species by its soft membranaceous basidiomata with cream to buff, smooth, cracked hymenial surface, a monomitic hyphal system with clamped generative hyphae and subcylindrical to allantoid basidiospores measuring 12–17.5 × 6.5–9 µm.

Holotype.

China • Yunnan Province, Dali, Weishan County, Leqiu Town, Zhongyao Village, 25°01′N, 100°19′E, altitude 1910 m, on the fallen branch of angiosperm, leg. C.L. Zhao, 19 July 2022, CLZhao 22774 (SWFC).

Etymology.

albomarginata (Latin or Greek origin): referring to the white margin of the basidiomata.

Basidiomata.

Annual, resupinate, closely adnate, soft membranaceous, very hard to separate from substrate, without odour or taste when fresh, becoming coriaceous upon drying, up to 5 cm long, 1.5 cm wide, 50–100 µm thick. Hymenial surface smooth, white to cream when fresh, turning to cream to buff upon drying, cracked. Sterile margin white, thinning out, up to 0.5 mm wide.

Hyphal system.

Monomitic, generative hyphae with clamp connections, colourless, thin-walled, unbranched, interwoven, 2.5–3.5 µm in diameter; IKI–, CB–, tissues unchanged in KOH. Hymenium. Cystidia numerous, thin-walled, subclavate to fusiform with an acute or obtuse apex, occasionally sinuous in the basal, 23.5–48.5 × 10–13.5 µm, with a clamp connection at base; cystidioles absent. Hyphidia arising from generative hyphae, nodulose, branched, colourless, thin-walled, 2.5–5 µm in diameter. Basidia ellipsoid to ovoid, longitudinally septate, two to four-celled, 17–24.5 × 11–16.5 µm; basidioles dominant, similar to basidia in shape, but slightly smaller. Basidiospores. Subcylindrical to allantoid, slightly curved, colourless, smooth, thin-walled, with 1–2 oil drops, IKI–, CB–, (11.5–)12–17.5(–18) × 6.5–9(–9.5) µm, L = 14.66 µm, W = 7.80 µm, Q = 1.72–1.99, Q_m = 1.88 ± 0.08 (n = 30/1).

. Adustochaete punctata

J.H Dong & C.L. Zhao sp. nov.

7CFE9A66-C65B-593E-876E-BFC40F3BEA23

854170

Figs 7 , 8 , 9

Figure 7.

Basidiomata of Adustochaetepunctata in general and detailed views (CLZhao 29675, holotype). Scale bars: 1 cm (A); 1 mm (B).

Figure 8.

Sections of hymenium of Adustochaetepunctata (holotype, CLZhao 29675) A basidiospores B basidia C cystidia D hyphidia. Scale bars: 20 µm (A–D); 10 × 100 Oil.

Figure 9.

Microscopic structures of Adustochaetepunctata (holotype, CLZhao 29675) A basidiospores B basidia C basidioles D cystidia E hyphidia F part of the vertical section of hymenium. Scale bars: 10 µm (A–F).

Diagnosis.

Differs from other Adustochaete species by its membranaceous basidiomata with cream, smooth, punctate hymenial surface, a monomitic hyphal system with clamped generative hyphae and subcylindrical to allantoid basidiospores measuring 13.5–18 × 6–8.2 µm.

Holotype.

China • Yunnan Province, Dehong, Yingjiang County, Tongbiguan Provincial Nature Reserve, 23°48′N, 97°38′E, altitude 1500 m, on the fallen branch of angiosperm, leg. C.L. Zhao, 17 July 2023, CLZhao 29675 (SWFC).

Etymology.

punctata (Latin or Greek origin): referring to the punctate hymenial surface of the specimen.

Basidiomata.

Annual, resupinate, closely adnate, membranaceous, very hard to separate from substrate, without odour or taste when fresh, becoming coriaceous upon drying, up to 10 cm long, 1.5 cm wide, 100–250 µm thick. Hymenial surface smooth, punctate, white to cream when fresh, turning to cream upon drying. Sterile margin cream, thinning out, up to 1 mm wide.

Hyphal system.

Monomitic, generative hyphae with clamp connections, colourless, thin-walled, unbranched, interwoven, 1.5–3.5 µm in diameter; IKI–, CB–, tissues unchanged in KOH. Hymenium. Cystidia numerous, thin-walled, subcylindrical to clavate with an obtuse apex, occasionally sinuous in the basal, 15.5–23.5 × 5.5–7.5 µm, with a clamp connection at base; cystidioles absent. Hyphidia arising from generative hyphae, nodulose, branched, colourless, thin-walled, 1.5–5 μm in diameter. Basidia ellipsoid to ovoid, longitudinally septate, two to four-celled, 17–25 × 16.5–21 µm; basidioles dominant, similar to basidia in shape, but slightly smaller. Basidiospores. Subcylindrical to allantoid, slightly curved, colourless, smooth, thin-walled, with several oil drops, IKI–, CB–, (13–)13.5–18(–18.5) × (5.5–)6–8.2(–8.5) µm, L = 15.78 µm, W = 6.79 µm, Q = 2.15–2.40 Q_m = 2.32 ± 0.08 (n = 90/3).

Additional specimens examined.

China • Yunnan Province, Dehong, Yingjiang County, Tongbiguan Provincial Nature Reserve, 23°48′N, 97°38′E, altitude 1500 m, on the fallen branch of angiosperm, leg. C.L. Zhao, 17 July 2023, CLZhao 29669; CLZhao 29671; CLZhao 29685; CLZhao 29686; CLZhao 29706; CLZhao 29710; CLZhao 29711 (SWFC).

. Alloexidiopsis grandinea

J.H Dong & C.L. Zhao sp. nov.

E5A16478-6DE6-54DD-92AC-32E3CFE78F86

854171

Figs 10 , 11 , 12

Figure 10.

Basidiomata of Alloexidiopsisgrandinea in general and detailed views (CLZhao 33798, holotype). Scale bars: 1 cm (A); 1 mm (B).

Figure 11.

Sections of hymenium of Alloexidiopsisgrandinea (holotype, CLZhao 33798) A basidiospores B basidia C cystidia D hyphidia. Scale bars: 10 µm (A); 20 µm (B–D); 10 × 100 Oil.

Figure 12.

Microscopic structures of Alloexidiopsisgrandinea (holotype, CLZhao 33798) A basidiospores B basidia C basidioles D cystidia E hyphidia F part of the vertical section of hymenium. Scale bars: 10 µm (A–F).

Diagnosis.

Differs from other Alloexidiopsis species by its membranaceous basidiomata with buff to slightly yellowish, grandinioid hymenial surface, a monomitic hyphal system with clamped generative hyphae and cylindrical to allantoid basidiospores measuring 10–12.3 × 5–5.8 µm.

Holotype.

China • Yunnan Province, Zhaotong, Wumengshan National Nature Reserve, 28°03′N, 104°20′E, altitude 1500 m, on the fallen branch of angiosperm, leg. C.L. Zhao, 21 September 2023, CLZhao 33798 (SWFC).

Etymology.

grandinea (Latin or Greek origin): referring to the grandinioid hymenial surface.

Basidiomata.

Annual, resupinate, closely adnate, membranaceous, very hard to separate from substrate, without odour or taste when fresh, becoming coriaceous upon drying, up to 20 cm long, 3 cm wide, 50–100 µm thick. Hymenial surface grandinioid, white to buff when fresh, turning to buff to slightly yellowish upon drying. Sterile margin cream to buff, thinning out, up to 1 mm wide.

Hyphal system.

Monomitic, generative hyphae with clamp connections, colourless, thin-walled, rarely branched, interwoven, 2–4 µm in diameter; IKI–, CB–, tissues unchanged in KOH. Hymenium. Cystidia numerous, thin-walled, fusiform with an acute apex, occasionally sinuous in the basal, 20–42.5 × 5.5–9.5 µm, with a clamp connection at base; cystidioles absent. Hyphidia arising from generative hyphae, nodulose, frequently branched, colourless, thin-walled, 2–5 µm in diameter. Basidia ellipsoid to ovoid, longitudinally septate, two to four-celled, 12.5–14.5 × 9–11.5 µm; basidioles dominant, similar to basidia in shape, but slightly smaller. Basidiospores. Cylindrical to allantoid, slightly curved, colourless, smooth, thin-walled, with 1–2 oil drops, IKI–, CB–, (9.5–)10–12.3(–12.5) × (4.8–)5–5.8(–6) µm, L = 11.08 µm, W = 5.38 µm, Q = 1.95–2.20, Q_m = 2.06 ± 0.04 (n = 60/2).

Additional specimen examined.

China • Yunnan Province, Diqing, Weixi County, Weiden Town, Fuchuan Village, 27°06′N, 99°10′E, altitude 2900 m, on the fallen branch of angiosperm, leg. C.L. Zhao, 12 October 2023, CLZhao 34279 (SWFC).

. Alloexidiopsis xantha

J.H. Dong & C.L. Zhao sp. nov.

41994D3C-BA51-5BCA-9B54-998A6CDECB73

854172

Figs 13 , 14 , 15

Figure 13.

Basidiomata of Alloexidiopsisxantha in general and detailed views (CLZhao 25093, holotype). Scale bars: 1 cm (A); 1 mm (B).

Figure 14.

Sections of hymenium of Alloexidiopsisxantha (holotype, CLZhao 25093) A basidiospores B basidia C hyphidia D cystidia. Scale bars: 20 µm (A–D); 10 × 100 Oil.

Figure 15.

Microscopic structures of Alloexidiopsisxantha (holotype, CLZhao 25093) A basidiospores B basidioles C cystidia D basidia E hyphidia F part of the vertical section of hymenium. Scale bars: 10 µm (A–F).

Diagnosis.

Differs from other Alloexidiopsis species by its coriaceous basidiomata with cream to buff to yellow, smooth, slightly cracked hymenial surface, a monomitic hyphal system with clamped generative hyphae and allantoid to sickle-shaped basidiospores measuring 20–24 × 5–6.2 µm.

Holotype.

China • Yunnan Province, Lincang, Yun County, Dumu Village, 24°32′N, 100°23′E, altitude 2100 m, on the fallen branch of angiosperm, leg. C.L. Zhao, 20 October 2022, CLZhao 25093 (SWFC).

Etymology.

xantha (Latin or Greek origin): referring to the buff to yellow hymenial surface of the type specimen.

Basidiomata.

Annual, resupinate, closely adnate, coriaceous, very hard to separate from substrate, without odour or taste when fresh, becoming leathery upon drying, up to 10 cm long, 2 cm wide, 200–300 µm thick. Hymenial surface smooth, slightly cracked, cream when fresh, turning to cream to buff to yellow upon drying. Sterile margin cream, thinning out, up to 1 mm wide.

Hyphal system.

Monomitic, generative hyphae with clamp connections, colourless, thin- to thick walled, branched, interwoven, 2.5–3.5 µm in diameter; IKI–, CB–, tissues unchanged in KOH. Hymenium. Cystidia numerous, thin-walled, subcylindrical to subconiform with an obtuse apex, 12.5–17.5 × 3.5–6 µm, with a clamp connection at base; cystidioles absent. Hyphidia arising from generative hyphae, nodulose, frequently branched, colourless, thin-walled, 2.5–4 µm in diameter. Basidia ellipsoid to ovoid, obconical, longitudinally septate, two to four-celled, 18–20.5 × 12–15.5 µm; basidioles dominant, similar to basidia in shape, but slightly smaller. Basidiospores. Allantoid, curved, sickle-shaped, colourless, smooth, thin-walled, IKI–, CB–, (18.5–)20–24(–24.5) × 5–6.2(–6.5) µm, L = 21.66 µm, W = 5.63 µm, Q = 3.60–4.05, Q_m = 3.85 ± 0.10 (n = 30/1).

Discussion

In the present study, four new species Ad.albomarginata, Ad.punctata, Al.grandinea and Al.xantha are described, based on the phylogenetic analyses and morphological characteristics.

The corticioid species of the order Auriculariales are traditionally placed in Eichleriella, Exidiopsis and Heterochaete according to the morphological characteristics (Liu et al. 2022). On the basis of the erection of six new genera as Adustochaete, Alloexidiopsis, Amphistereum, Crystallodon, Proterochaete and Sclerotrema, they were placed in the corticioid species and three previously known genera were reinstated, for example, Hirneolina, Heteroradulum and Tremellochaete (Malysheva and Spirin 2017; Alvarenga et al. 2019; Alvarenga and Gibertoni 2021; Liu et al. 2022). A multilocus-based phylogeny with a wider sampling of various morphological groups in Auriculariales is urgently needed to achieve a more natural classification of this order, as in other orders within Agaricomycetes (Wang et al. 2021).

Phylogenetically, based on the combined ITS+nLSU sequence data (Fig. 1), it demonstrated that the four new species were nested in the genera Adustochaete and Alloexidiopsis within the order Auriculariales. Based on ITS topology tree (Fig. 2), Ad.albomarginata was retrieved as a sister to Ad.yunnanensis and the species Ad.punctata was sister to Ad.rava. However, Ad.yunnanensis differs from Ad.albomarginata by its grandinioid hymenial surface, longer basidia (25–47.5 × 8.5–14 µm) and smaller cystidia (17.5–24.5 × 3.5–5.8 µm; Li and Zhao (2022)). Ad.rava can be distinguished from Ad.punctata by its spined, sharp-tipped hymenial surface, smaller basidia (14.9–16.2 × 9.7–10.1 μm) and basidiospores (10.2–13.6 × 4.6–5.9 µm; Hyde et al. (2020)). Based on ITS topology tree (Fig. 3), Al.grandinea was retrieved as a sister to Al.schistacea and Al.xantha formed a monophyletic lineage. However, Al.schistacea differs from Al.grandinea by its smooth hymenial surface and longer basidia (15–20 × 7–10 µm; Liu et al. (2022)).

Morphologically, two new species Adustochaetealbomarginata and Ad.punctata resemble four similar species in the genus Adustochaete, Ad.interrupta Spirin & Malysheva, Ad.nivea, Ad.rava and Ad.yunnanensis. A morphological comparison between two new Adustochaete species and four similar species are presented in Table 2. Two new species Al.grandinea and Al.xantha are similar to five species in the genus Alloexidiopsis, Al.australiensis S.L. Liu, Z.Q. Shen & L.W. Zhou, Al.calcea (Pers.) L.W. Zhou & S.L. Liu, Al.nivea (J.J. Li & C.L. Zhao) L.W. Zhou & S.L. Liu, Al.schistacea and Al.yunnanensis. A morphological comparison between two new Alloexidiopsis species and six similar species are presented in Table 3.

Table 2.

A morphological comparison between two new Adustochaete species and four similar species in the genus Adustochaete.

Species name	Hymenial surface	Hyphae	Cystidia	Basidia	Basidiospores	References
Adustochaetealbomarginata	Smooth/ Cream to buff	Thin-walled, unbranched	Subclavate to fusiform; 23.5–48.5 × 10–13.5 µm	Ellipsoid to ovoid, two to four-celled; 17–24.5 × 11–16.5 µm	Subcylindrical to allantoid; 12–17.5 × 6.5–9 µm	Present study
Adustochaeteinterrupta	Smooth/ Light ochraceous-grey to brownish	Thin-walled	Clavate to fusiform; 45–96 × 6–13.5 µm	Narrowly ovoid to obconical, four-celled; 15.1–24 × 9.1–11.8 µm	Broadly cylindrical; 11.3–14.3 × 5.7–6.2 µm	Alvarenga et al. (2019)
Adustochaetenivea	Sharp-tipped spines/ White	Thin-walled	—	Narrowly ovoid to obconical, four-celled; 14.9–16.2 × 9.7–10.1 μm	Cylindrical; 10.2–13.6 × 4.6–5.9 µm	Hyde et al. (2020)
Adustochaetepunctata	Smooth/ Punctate, white to cream	Thin-walled, unbranched	Subcylindrical to clavate; 15.5–23.5 × 5.5–7.5 µm	Ellipsoid to ovoid, two to four-celled; 17–25 × 16.5–21 µm	Subcylindrical to allantoid; 13.5–18 × 6–8.2 µm	Present study
Adustochaeterava	Sharp-tipped spines/ Pale to dark grey	Thin-walled	Clavate to fusiform; 27–52 × 4–8 µm	Narrowly ovoid to obconical, four-celled; 10.8–15.2 × 7.3–10 µm	Cylindrical; 10.2–13.7 × 3.8–4.7 µm	Alvarenga et al. (2019)
Adustochaeteyunnanensis	Grandinioid/ Dark greyish to brownish	Thin-walled, branched	Clavate to fusiform; 17.5–24.5 × 3.5–5.8 µm	Narrowly ovoid to obconical, four-celled; 25–47.5 × 8.5–14 µm	Narrow cylindrical to allantoid; 12–20 × 5–7 µm	Li and Zhao (2022)

Table 3.

A morphological comparison between two new Alloexidiopsis species and six similar species in the genus Alloexidiopsis.

Species name	Hymenial surface	Hyphae	Cystidia	Basidia	Basidiospores	References
Alloexidiopsisaustraliensis	Smooth, covered by sterile spines/ Cream to pale orange	Thin-walled, branched	Cylindrical, ventricose; 21.5–24.5 × 9.5–12 µm	Ellipsoid to ovoid, four-celled; 18–21 × 13–18 µm	Cylindrical to broadly cylindrical; 13–25 × 7–11 µm	Li et al. (2022b)
Alloexidiopsiscalcea	Granulose to pruinose/ Greyish-white to light ochraceous	Thin-walled, branched	—	Obovate to clavate, two to four-celled; 14–25 × 9.5–15 µm	Allantoid to cylindrical, sometimes helicoid; 12–18 × 5–7 µm	Wells (1961)
Alloexidiopsisgrandinea	Grandinioid/ Buff to slightly yellowish	Thin-walled, branched	Fusiform; 20–42.5 × 5.5–9.5 µm	Ellipsoid to ovoid, two to four-celled; 12.5–14.5 × 9–11.5 µm	Cylindrical to allantoid; 10–12.3 × 5–5.8 µm	Present study
Alloexidiopsisnivea	Smooth/ White to slightly cream	Thin-walled, unbranched	Tubular; 15–34 × 2.5–7 µm	Narrowly ovoid to obconical, two to four-celled; 9–19 × 8–15 µm	Allantoid; 6.5–13.5 × 2.7–5.5 µm	Li et al. (2022a)
Alloexidiopsisschistacea	Smooth/ Greyish	Thin-walled, branched	Cylindrical; 25–50 × 4–6 µm	Ellipsoid to ovoid, four-celled; 15–20 × 7–10 µm	Cylindrical to broadly cylindrical; 9.5–11 × 4.5–5.5 µm	Liu et al. (2022)
Alloexidiopsissinensis	Grandinoid/ Yellowish-brown to rose to slightly purple	Thin- to thick-walled, branched	Cylindrical; 11.5–15.5 × 3–5.5 µm	Ellipsoid to ovoid, two to four-celled; 16–22 × 7.5–10 µm	Allantoid; 14.5–23 × 4.5–6.5 µm	Dong et al. (2024)
Alloexidiopsisxantha	Smooth/ Cream to slightly buff	Thin- to thick walled, branched	Subcylindrical to subconiform; 12.5–17.5 × 3.5–6 µm	Ellipsoid to ovoid, obconical; 18–20.5 × 12–15.5 µm	Allantoid, sickle-shaped; 20–24 × 5–6.2 µm	Present study
Alloexidiopsisyunnanensis	Odontoid/ White to smoke grey	Thin-walled, unbranched	Clavate to fusiform; 13–35 × 2–6 µm	Narrowly ovoid to obconical, two to three-celled; 28–41 × 9–14 µm	Cylindrical; 17–24 × 5–8 µm	Guan et al. (2020)

In the ecological distribution, both genera species are not an extensively studied group, distributed worldwide and mainly found on hardwood (Alvarenga et al. 2019; Liu et al. 2022). The species of Adustochaeteinterrupta Spirin & Malysheva was found in Mexico, Ad.nivea was described in Brazil, Ad.rava was found in Brazil and Ad.yunnanensis was found in China. The species of Alloexidiopsisaustraliensis was found in Australia, Al.calcea was found in Germany and Al.nivea, Al.schistacea, Al.sinensis and Al.yunnanensis were found in China.

Fungi are one of the most diverse groups of organisms on Earth and play a crucial role in ecosystem processes and functions (Hyde 2022). New DNA sequencing techniques have revolutionised the studies of fungal taxonomy and diversity, in which about 150 k species of fungi have been described (Hyde 2022). In recent years, the wood-inhabiting fungi are an extensively studied group of Basidiomycota, which includes a number of poroid, smooth, grandinoid, odontioid and hydnoid basidiomata in China (Wu et al. 2022a, 2022b; Dong et al. 2023a, 2023b; Guan et al. 2023; Liu et al. 2023; Mao et al. 2023; Yang et al. 2023, 2024; Deng et al. 2024; Li et al. 2024; Luo et al. 2024; Zhang et al. 2024; Zhao et al. 2024; Zhou et al. 2024). In the past several years, many corticioid species have been reported and described in the order Auriculariales (Malysheva and Spirin 2017; Alvarenga et al. 2019; Spirin et al. 2019a, 2019a; Alvarenga and Gibertoni 2021; Li et al. 2022a, 2022b; Li and Zhao 2022; Liu et al. 2022), but many new taxa have not yet been discovered. Thus, the corticioid species diversity of the order Auriculariales is still not well known in China, especially in the subtropical and tropical areas. In the present study, four new species, Ad.albomarginata, Ad.punctata, Al.grandinea and Al.xantha were found and reported. This paper enriches our knowledge of fungal diversity in the order Auriculariales. We anticipate that more undescribed corticioid taxa will be discovered throughout China after extensive collection combined with morphological and molecular analyses.

Key to the known species of Adustochaete worldwide

1	Hymenial surface smooth	2
–	Hymenial surface grandinioid	4
2	Basidia > 16.5 µm wide	Adustochaetepunctata
–	Basidia < 16.5 µm wide	3
3	Basidiospores > 6.5 µm wide	Adustochaetealbomarginata
–	Basidiospores < 6.5 µm wide	Adustochaeteinterrupta
4	Cystidia absent	Adustochaetenivea
–	Cystidia present	5
5	Basidiospores > 5 µm wide, basidia > 16 µm long	Adustochaeteyunnanensis
–	Basidiospores < 5 µm wide, basidia < 16 µm long	Adustochaeterava

Key to the known species of Alloexidiopsis worldwide

1	Basidiospores allantoid	2
–	Basidiospores cylindrical	6
2	Hymenial surface smooth	3
–	Hymenial surface grandinoid, granulose to pruinose	4
3	Basidiospores > 13.5 µm long, cystidia subcylindrical to subconiform	Alloexidiopsisxantha
–	Basidiospores < 13.5 µm long, cystidia tubular	Alloexidiopsisnivea
4	Cystidia absent	Alloexidiopsiscalcea
–	Cystidia present	5
5	Cystidia > 5.5 µm wide	Alloexidiopsisgrandinea
–	Cystidia < 5.5 µm wide	Alloexidiopsissinensis
6	Basidia > 28 µm long, cystidia clavate to fusiform	Alloexidiopsisyunnanensis
–	Basidia < 28 µm long, cystidia cylindrical	7
7	Basidiospores > 11 µm long, cystidia < 25 µm long	Alloexidiopsisaustraliensis
–	Basidiospores < 11 µm long, cystidia > 25 µm long	Alloexidiopsisschistacea

Citation

Dong J, Zhu Y, Qian C, Zhao C (2024) Taxonomy and phylogeny of Auriculariales (Agaricomycetes, Basidiomycota) with descriptions of four new species from south-western China. MycoKeys 108: 115–146. https://doi.org/10.3897/mycokeys.108.128659

Funding Statement

The research was supported by the National Natural Science Foundation of China (Project Nos. 32170004, U2102220), Forestry Innovation Programs of Southwest Forestry University (Grant No: LXXK-2023Z07), the High-level Talents Program of Yunnan Province (YNQR-QNRC-2018-111), and the Research Project of Key Laboratory of Forest Disaster Warning and Control in Universities of Yunnan Province (ZKJS-S-202208)

Additional information

Conflict of interest

The authors have declared that no competing interests exist.

Ethical statement

No ethical statement was reported.

Funding

The research was supported by the National Natural Science Foundation of China (Project Nos. 32170004, U2102220), Forestry Innovation Programs of Southwest Forestry University (Grant No: LXXK-2023Z07), the High-level Talents Program of Yunnan Province (YNQR-QNRC-2018-111) and the Research Project of Key Laboratory of Forest Disaster Warning and Control in Universities of Yunnan Province (ZKJS-S-202208).

Author contributions

Conceptualisation, CZ and JD; methodology, CZ and JD; software, CZ, JD and YZ; validation, CZ and JD; formal analysis, CZ and J JD; investigation, CZ and JD; resources CZ; writing – original draft preparation, CZ, JD, YZ and CQ; writing – review and editing, CZ and JD; visualisation, CZ and JD; supervision, CZ and JD; project administration, CZ; funding acquisition, CZ. All authors have read and agreed to the published version of the manuscript.

Author ORCIDs

Junhong Dong https://orcid.org/0000-0001-8740-0805

Yonggao Zhu https://orcid.org/0009-0008-5341-3796

Chengbin Qian https://orcid.org/0009-0003-5329-1016

Changlin Zhao https://orcid.org/0000-0002-8668-1075

Data availability

All of the data that support the findings of this study are available in the main text.